JP5917135B2 - Sheet for skin application - Google Patents

Description

  The present invention relates to a sheet for skin application used by being applied to human skin.

  2. Description of the Related Art Conventionally, a method of cooling a forehead or the like by using a cloth or nonwoven fabric soaked with water when dealing with a sudden heat generation is known. However, such a method has a short cooling time, so that it is necessary to re-immerse water in cold water frequently, and it is difficult to move freely, so that it is not convenient.

In recent years, in order to improve such convenience, a cooling gel sheet in which a support layer such as a nonwoven fabric is combined with a water retaining layer made of a water-containing polymer gel has been developed (for example, Patent Documents 1 and 2). Such a cooling gel sheet is cooled by utilizing the heat of vaporization of water when water in the water-containing polymer gel layer evaporates, so that a cooling action can be obtained simply by sticking. On the other hand, the skin temperature rises as time elapses after application, and an unpleasant sensation such as wilt is likely to occur, and the cooling feeling is gradually lost. Must be replaced frequently. The nonwoven fabric used for such a cooling gel sheet has properties of a thickness of 0.3 to 5 mm, a basis weight of 30 to 200 g / m ² , and a fiber diameter of about 3 to 30 μm (for example, Patent Document 3).

JP 2002-241746 A JP 2000-185069 A JP 2003-313110 A

  In order to lengthen the cooling duration in the cooling gel sheet preparation as described above, a means for delaying the moisture evaporation rate in a support such as a nonwoven fabric may be taken, but the cooling action may be weakened. It is also possible to increase the heat capacity by increasing the thickness of the hydrous polymer gel layer, but this also reduces heat conductivity from the skin to the atmosphere and makes it easier for heat to accumulate in the polymer gel. Cooling action may be weakened. On the other hand, such a cooling gel sheet is not only used favorably when it generates heat such as a cold because of its high convenience, but also recently, it is often used to suppress the hot feeling in summer, and the usage scene is diverse. It is becoming. For this reason, there is an increasing demand for a sheet preparation that can sufficiently respond to a wide range of usage situations and can continuously provide a high cooling effect.

  Accordingly, an object of the present invention is to provide a sheet preparation that exhibits a long lasting cooling effect and also provides a pleasant cooling feeling.

  Therefore, the present inventors have conducted intensive studies to solve the above problems, and as a result, the hydrous polymer is a polymer hydrogel in which the dispersion medium is water, the dispersoid is a polymer, and a network structure is formed by crosslinking. By laminating a nanofiber layer, which is a very thin fiber layer having a nano-order fiber diameter that does not exist in a conventional cooling gel sheet, the nanofiber layer promotes heat dissipation from the skin well. Since the nanofiber layer can reduce the transpiration of water contained in the water-containing polymer gel layer, the heat of vaporization of water can be utilized for a long time, while exhibiting a high cooling effect. The present inventors have found that a pleasant cool feeling can be maintained and have completed the present invention.

  That is, the present invention provides a skin patch sheet in which a nanofiber layer having a network structure is laminated on a hydrous polymer gel layer.

  According to the present invention, it is possible to maintain a high cooling effect and a pleasant cooling feeling by utilizing the heat of vaporization of water for a long time while having good convenience.

It is a figure which shows the moisture transpiration rate (%) in the nanofiber sheet of the reference example 1, and the nonwoven fabric of the reference examples 2-3. It is a figure which shows the temperature change of the skin at the time of sticking the sheet | seat of Example 1 and Comparative Examples 1-3 to skin. It is a figure which shows the temperature change of the skin at the time of sticking the sheet | seat of Examples 1-3 to skin. It is a figure which shows the temperature change of the skin at the time of sticking the sheet | seat of Examples 4-5 and Comparative Examples 4-5 on skin. It is a figure which shows the result of having performed sensory evaluation of Example 1 and Example 6. FIG.

Hereinafter, the present invention will be described in detail.
The skin patch sheet of the present invention is used by sticking to human skin, and is formed by laminating a nanofiber layer having a network structure on a hydrous polymer gel layer.
The water-containing polymer gel layer is a layer formed by swelling a gel formed of a polymer while retaining a large amount of water. When the skin patch sheet of the present invention is applied to the skin, heat is transferred from the skin to the gel layer by direct contact with the water-containing polymer gel layer, and then the water in the gel layer evaporates and vaporizes from the skin. Cool the skin by taking away heat. On the other hand, in the nanofiber layer laminated on the water-containing polymer gel layer, the water evaporating from the water-containing polymer gel layer can easily pass through without being retained and released from the sheet, as will be described later. Since it accelerates | stimulates, the water in a gel evaporates continuously and can fully exhibit the cooling effect over a long time.

  The water content in the water-containing polymer gel layer is preferably 40 to 99% by mass, more preferably 50 to 98% by mass, from the viewpoint of continuously cooling the skin by the heat of vaporization of water and the shape retention. More preferably, it is 70-97 mass%, More preferably, it is 80-96 mass%.

  The thickness of the hydrous polymer gel layer may vary depending on its composition, but in combination with the action brought about by the nanofiber layer described later, the gel maintains a high cooling effect for a long time while supplying a sufficient amount of water, and the gel From the viewpoint of ensuring good thermal conductivity by avoiding heat storage inside, it is preferably 0.01 mm to 2 mm, more preferably 0.1 to 1.5 mm, and further preferably 0.1 to 1 mm. is there.

  The polymer that forms the water-containing polymer gel layer is not particularly limited as long as it can form a gel having appropriate elasticity, elasticity, and flexibility while retaining water and swelling. , A polymer having a functional group such as a sulfate group or a phosphate group. Specific examples include anionic cellulose derivatives such as carboxyvinyl polymer, carboxymethylcellulose, and carboxyethylcellulose, carrageenan, alginic acid and salts thereof, anionic starch derivatives, and the like. Among these, poly (meth) acrylic acid, anion from the viewpoint of having a high water retention amount, sufficient gel strength, flexibility of following the unevenness of the skin and its movement, and a higher water content. Cellulose derivative and carrageenan are preferable, and carboxymethylcellulose is more preferable. The content of these polymers is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and still more preferably 0.5 to 5% by mass in the hydrous polymer gel layer. It is good to mix | blend with gel stock solution by the quantity used as this content.

  When forming a gel with the polymer, it is preferable to react with a functional group of the polymer using a crosslinking agent. Such cross-linking agents include metal ion compounds such as oxides, hydroxides and salts containing aluminum, magnesium, calcium, potassium, etc .; cationic polymers such as polyamino acids such as polylysine; ethylene glycol diglycidyl ether, polyethylene Examples thereof include polyfunctional epoxy compounds such as glycol diglycidyl ether, glycerin diglycidyl ether, and glycerin triglycidyl ether.

  The water-containing polymer gel layer preferably contains a cooling agent from the viewpoint of exhibiting a sufficient cooling feeling. As a result, a good cooling sensation can be imparted to further amplify the cooling sensation.For example, the skin patch sheet of the present invention can be used for more sustainable and high cooling effects, such as during outdoor activities in summer. It is suitable for use in a scene where the user desires.

  Examples of cooling sensitizers include l-menthol, isopulegol, 3- (l-menthoxy) propane-1,2-diol, p-menthane-3,8-diol, 6-isopropyl-9-methyl-1,4-dioxaspiro. -(4,5) -decane-2-methanol, menthyl succinate and its alkaline earth salts, trimethylcyclohexanol, N-ethyl-2-isopropyl-5-methylcyclohexanecarboxamide, 3- (l-menthoxy) -2 -Methyl-propane-1,2-diol, mint oil, peppermint oil, winter green, menthone, menthone glycerin ketal, menthyl lactate, camphor and the like. Of these, l-menthol, menthyl lactate, and camphor are preferable from the viewpoint of maintaining a pleasant cool feeling for a long time. The content of these cooling sensates is preferably 0.0001 to 10% by mass, more preferably 0.001 to 5% by mass, and still more preferably 0.01 to 1% by mass in the hydrous polymer gel layer. .

  Normally, the pH of normal human skin is in the range of 4-6, and if the skin pH fluctuates more than necessary, the function of the skin will be hindered. It is preferable to be within the above range. Therefore, the pH of the gel stock solution forming the water-containing polymer gel layer is preferably 7.5 or less, more preferably 3.5 to 6.5 from the viewpoint of taking into account the safety at the time of application. More preferably, it is 4.0 to 6.0. Such pH may be adjusted by appropriately using a pH adjuster so that the final pH is within the above range. As the pH adjuster, for example, organic acids such as succinic acid, citric acid and tartaric acid or salts thereof, or phosphoric acid or salts thereof are preferably used.

  In addition to the above components, the water-containing polymer gel layer generally includes other components commonly used in cosmetics and pharmaceuticals, such as glycerin, diglycerin, polyglycerin, 1,3-butylene glycol, propylene glycol, and dipropylene glycol. Moisturizer such as polyethylene glycol, oil agent, surfactant such as anionic surfactant, cationic surfactant, amphoteric surfactant and nonionic surfactant; medicinal component; preservative such as paraoxybenzoate ester; UV absorbers; Solubilizers; Colorants; "Synthetic perfume chemistry and product knowledge", Motoichi Into, 1996 published by Chemical Daily, "Perfume and Flavor Chemicals", Stefan Arctan By STEFENARCTAMDER, 196 A perfume or the like may be appropriately be contained as described in the literature of the year, or the like.

  In order to produce a hydrous polymer gel layer, for example, first, a gel stock solution containing the above-mentioned polymer forming the same, water, and if necessary, a cooling sensation agent and other components is prepared. Next, the gel stock solution is sandwiched between a peelable film and a non-woven fabric, and spread using a baker type applicator or the like. At this time, it is good also considering one surface which pinches | interposes a gel stock solution as a nano-fiber layer. Then, a hydrous polymer gel layer is obtained by aging for several days under heating.

  The nanofiber layer having a network structure is a layer that is directly laminated on one surface of the water-containing polymer gel layer, and a fine network structure is formed by nanofibers having a fiber diameter in the nano order. The nanofiber constituting the layer is generally a solid fiber, but is not limited thereto, and may be, for example, a hollow nanofiber, or a ribbon-like nanofiber having a shape in which the hollow nanofiber is crushed in the cross-sectional direction. It may be. Moreover, the whole nanofiber should just form the network structure, and about each nanofiber, at least one part may exist in the state orientated in one direction, or it is orientated in the random direction. Also good.

  The average fiber diameter of the nanofibers is preferably 50 nm or more and less than 2000 nm, more preferably 50 nm or more and less than 1000 nm, and even more preferably 50 nm or more, from the viewpoint of increasing the specific surface area to retain and evaporate more water. 800 nm. The average fiber diameter of the nanofiber is observed by magnifying the nanofiber at a magnification of 10,000 times by observation with a scanning electron microscope (SEM), and from the two-dimensional image, defects (nanofiber lump, nanofiber intersection) , Nanofibers (drops of nanofiber raw material liquid) are arbitrarily selected from 10 nanofibers, the fiber diameter is measured when a line perpendicular to the longitudinal direction of the fiber is drawn, and the mean value obtained from these values is meant To do.

  The length of the nanofiber can be used as a fiber as long as it is 100 times or more the fiber diameter, and may be appropriately selected depending on the production method.

The basis weight of the nanofibers in the nanofiber layer may be appropriately selected according to the use of the skin patch sheet, but it does not inhibit the transpiration of moisture contained in the hydrous polymer gel layer, and this effect is prolonged. from the viewpoint of sustaining over, is preferably from 0.01 to 100 g / m ^2, more preferably from 0.1 to 50 g / m ^2, even more preferably in the range of 0.1 to 20 g / m ² .

  The thickness of the nanofiber layer can be appropriately selected according to the use of the skin patch sheet, but does not inhibit the transpiration of moisture contained in the hydrous polymer gel layer, and this effect is maintained over a long period of time. From the viewpoint of sustaining, the thickness is preferably 500 nm to 1 mm, more preferably 1 μm to 500 μm. In addition, the thickness of a nanofiber layer means the value measured using the contact-type film thickness meter Lightmatic VL-50A (R5mm super hard spherical surface probe) by Mitutoyo Corporation. The load applied to the nanofiber layer during measurement is 0.01 N.

Nanofibers are manufactured using a raw material solution containing a polymer compound. As the polymer compound, any of a natural polymer compound and a synthetic polymer compound can be used, but a hydrophilic polymer compound is preferable. Examples of the hydrophilic polymer compound include pullulan, hyaluronic acid, chondroitin sulfate, poly-γ-glutamic acid, modified corn starch, β-glucan, gluco-oligosaccharide, heparin, keratosulfuric acid and other mucopolysaccharides, cellulose, pectin, xylan, lignin. , Glucomannan, galacturon, psyllium seed gum, tamarind seed gum, gum arabic, tragacanth gum, soy water soluble polysaccharide, alginic acid, carrageenan, laminaran, agar (agarose), fucoidan, methylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, etc. Molecular compounds: partially saponified polyvinyl alcohol (when not used in combination with a crosslinking agent described later), low saponified polyvinyl alcohol, polyvinyl pyrrolidone (PVP), polyethylene oxide And synthetic polymer compounds such as sodium polyacrylate. These hydrophilic polymer compounds can be used alone or in combination of two or more. In the case of a polymer compound that completely dissolves in water after nanofiber formation, a crosslinking agent that reacts with a hydroxyl group, such as urea, melamine, or a phenol resin, is added to the hydrophilic polymer compound for water resistance treatment. It is preferable to perform water resistance treatment by performing crystallization by heat treatment. Among these, from the viewpoint of easy production of the nanofiber layer, it is preferable to use natural polymer compounds such as pullulan and synthetic polymer compounds such as partially saponified polyvinyl alcohol, low saponified polyvinyl alcohol, polyvinyl pyrrolidone, and polyethylene oxide. Polyvinyl alcohol is more preferable.
The raw material liquid contains an organic solvent such as alcohol as a solvent according to the type of the polymer compound.

Examples of the hydrophobic polymer compound include synthetic polymer compounds such as polyurethane, polystyrene, polylactic acid, polycarbonate, polyethylene terephthalate, polyacryl, polyester, and polyvinyl butyral.
The above-described hydrophilic polymer compound and hydrophobic polymer compound may be mixed to create nanofibers.

  In order to produce nanofibers, it is preferable to use an electrospinning method (electrospinning method). With such a method, it is easy to form nano-order fiber diameters into more uniform ultrafine fibers, and these can be directly deposited on the hydrous polymer gel layer to laminate the nanofiber layer.

  In order to carry out the electrospinning method, a syringe having a cylinder, a piston and a capillary, a high voltage source, and a conductive collector are used. The inner diameter of the capillary is preferably 10 to 1000 μm, and the cylinder is filled with a raw material liquid containing the above polymer compound. The high voltage source is, for example, a DC voltage source of 10 to 50 kV, and the positive electrode is connected to the raw material liquid in the syringe and the negative electrode is grounded. The conductive collector is grounded using, for example, a metal plate. What is necessary is just to set the distance between the front-end | tip of the needle in a syringe, and a conductive collector to about 30-300 mm, for example. Such an apparatus can be operated in the atmosphere, for example, in an environment having a temperature of 20 to 40 ° C. and a humidity of 10 to 50% RH.

  Next, under a state where a voltage is applied between the syringe and the conductive collector, the piston of the syringe is gradually pushed in, and the raw material liquid is pushed out from the tip of the capillary. In the extruded raw material liquid, the solvent is volatilized, the polymer compound as a solute is solidified, and nanofibers are formed while being stretched and deformed by a potential difference, and are drawn to the conductive collector. The nanofibers thus formed become continuous fibers having an infinite length in principle, and a nanofiber layer can be formed by being deposited on a smooth substrate.

  As described above, if the electrospinning method is used, not only can an ultrafine fiber having a uniform fiber diameter on the nano order be easily obtained, but a nanofiber can be formed on the layer by disposing a hydrous polymer gel layer as a substrate. It is also possible to obtain the sheet for skin application of the present invention in which layers are laminated.

The nanofiber layer preferably further contains a cooling sensate from the viewpoint of imparting a cooling feeling while promoting moisture transpiration of the water-containing polymer gel layer. As a result, a good cooling feeling can be imparted to amplify the cooling effect, which is effective, for example, when the skin patch sheet of the present invention is used outdoors. As a cooling sensation agent, the thing similar to the cooling sensation agent used with the said water-containing polymer gel layer can be used. The content of these cooling agents is preferably 0.0001 to 10% by mass, more preferably 0.001 to 5% by mass, and still more preferably 0.01 to 3% by mass in the nanofiber layer. It is good to mix | blend with a raw material liquid by the quantity used as content.
Such a cooling sensation agent may be contained in the water-containing polymer gel layer as described above, may be contained in the nanofiber layer, or may be contained in both layers.

  In addition to the above components, the nanofiber layer may appropriately contain other components similar to those of the water-containing polymer gel layer.

In order to produce the sheet for skin application of the present invention, a nanofiber layer may be placed on a separately formed hydrous polymer gel layer, and the hydrous polymer gel layer previously formed by electrospinning is used as a substrate. A nanofiber layer may be formed thereon.
The obtained sheet for skin application may be stored in a packaging pillow, and is laminated on one side, preferably a water-containing polymer gel layer, as a support layer with a film or sheet for peeling off after application to the skin. May be.

  The sheet for skin application of the present invention can cool the skin effectively and continuously by applying a water-containing polymer gel layer to the skin, and is a makeup for applying to the outer skin (including the scalp). Applications are wide-ranging as materials, pharmaceuticals, quasi-drugs and miscellaneous goods. For example, if you want to cool your forehead or neck during a sudden fever, or if you want to cool your feet, body, neck, or head before going to bed on a hot and uncomfortable night in the summer, you want to get a cool feeling outdoors in the summer In some cases, it can be used by sticking on the skin of a desired site.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples.

[Production Example 1: Production of nanofiber sheet A]
Polyvinyl alcohol (PVA, 117 manufactured by Kuraray Co., Ltd.) was dissolved in water to obtain a 12% by mass solution. This is filled in a solution filling part of an electrospinning apparatus (NF-102 manufactured by MEC Co., Ltd.), subjected to electrospinning by applying a voltage of 30 kV, and the obtained nanofiber sheet is subjected to heat treatment at 180 ° C. for 1 minute, Nanofiber sheet A was produced. The diameter of the metallic capillary used at this time was 0.22 mm in inner diameter, and the distance from the tip of the needle in the syringe to the conductive collector was 23 cm. The obtained nanofiber sheet A had a thickness of 100 μm, an average fiber diameter of 641 nm, and a basis weight of 18 g / m ² .

[Production Example 2: Production of nanofiber sheet B]
A nanofiber sheet C was produced in the same manner as in Production Example 1 except that polyurethane (DIC PU-116, manufactured by DIC Corporation) was dissolved in isopropyl alcohol and a 15% solution was used instead of polyvinyl alcohol. The obtained nanofiber sheet B had a thickness of 20 μm, an average fiber diameter of 450 nm, and a basis weight of 4.8 g / m ² ).

[Production Example 3: Production of nanofiber sheet C]
A nanofiber sheet D was produced in the same manner as in Production Example 1 except that polyvinyl alcohol (Kuraray Co., Ltd. PVA, 117) was dissolved in water to obtain a 10% by mass solution. The diameter of the metallic capillary used at this time was 0.22 mm in inner diameter, and the distance from the tip of the needle in the syringe to the conductive collector was 23 cm. The obtained nanofiber sheet C had a thickness of 100 μm, an average fiber diameter of 394 nm, and a basis weight of 18 g / m ² .

[Reference Examples 1-3]
Nanofiber sheet A obtained in Production Example 1 as Reference Example 1, Rayon nonwoven fabric (Nippon Vilene Co., Ltd. ED-5150, average fiber diameter of about 5000 to 20000 nm, basis weight 142 g / m ² ), and Reference As Example 3, a polyolefin non-woven fabric (Nippon Vilene Co., Ltd. ED-17, average fiber diameter of about 5000 to 20000 nm, basis weight of 170 g / m ² ) was used, and the temporal variation of each water transpiration rate (%) was compared. The results are shown in FIG.
The moisture transpiration rate was determined by the following method.

<Moisture transpiration rate (%)>
In a measurement environment with a temperature of 28 ± 1 ° C and a humidity of 60 ± 5% RH, 100 μL of water is placed on a polypropylene dish, and a nanofiber sheet or nonwoven fabric is placed on it. The amount of moisture change was measured and the moisture transpiration rate (%) was calculated from the following formula based on these values.
Moisture transpiration rate (%) = (total weight before start of measurement-total weight after a certain period of time) /0.1×100

  From the result of FIG. 1, the nanofiber sheet A of Production Example 1 has a significantly higher moisture transpiration rate than the rayon nonwoven fabric and the polyolefin nonwoven fabric, and also has an extremely high moisture transpiration rate, which is higher than that of the nonwoven fabric conventionally used for cooling sheet agents. It turns out that it is very useful.

[Example 1]
A mixed solution of glycerin and propylene glycol was put into a kneader, and carboxymethyl cellulose dispersed in an aqueous succinic acid solution, a dried aluminum hydroxide gel, and methyl parahydroxybenzoate were added in this order to prepare a gel stock solution. Next, the obtained gel stock solution is sandwiched between a polypropylene film as a support for peeling after sticking and the nanofiber sheet A obtained in Production Example 1, and the thickness of the gel stock solution is appropriately adjusted by a baker type applicator. Adjusted and extended. The obtained sheet was sealed in an aluminum pillow, sealed, and then aged at 50 ° C. for 5 days to proceed with the crosslinking reaction of the polymer in the gel stock solution to form a hydrous polymer gel layer. A laminated sheet was obtained. The obtained laminated sheet was cut into a square (area 25 cm ² ) and used as a measurement sample to be applied to the skin. The prepared gel stock solution had a pH of 4.5 to 6.5.
Using the obtained measurement sample, the amount of change in skin temperature over the pasting time was determined by the following method and used as an index of the cooling effect. The results are shown in FIG.

《Change in skin temperature (Δ ℃)》
The subject was a healthy male in his 30s, and a thermistor probe was previously attached to the forearm in a measurement environment of temperature 28 ± 1 ° C. and humidity 60 ± 5% RH, and the skin surface temperature before sticking the sheet was measured. Thereafter, the laminated sheet obtained in Example 1 was affixed to the skin from above the thermistor probe, and the skin surface temperature at the time when a predetermined time had elapsed from the affixation was measured three times to obtain the average value. Was used to calculate the skin temperature change.
Skin temperature change (Δ ° C) = (Skin temperature before application of sheet)-(Skin temperature after application of sheet)

[Comparative Example 1]
A laminated sheet having the structure shown in Table 1 was prepared in the same manner as in Example 1 except that the gel stock solution was sandwiched between the polypropylene film and the rayon nonwoven fabric used in Reference Example 2, and a measurement sample was obtained.
Using the obtained measurement sample, the amount of change in skin temperature was determined in the same manner as in Example 1. The results are shown in FIG.

[Comparative Example 2]
A laminated sheet having the structure shown in Table 1 was prepared in the same manner as in Example 1 except that the gel stock solution was sandwiched between the polypropylene film and the polyolefin nonwoven fabric used in Reference Example 3, and a measurement sample was obtained.
Using the obtained measurement sample, the amount of change in skin temperature was determined in the same manner as in Example 1. The results are shown in FIG.

[Comparative Example 3]
A single-layer sheet having the structure shown in Table 1 was obtained in the same manner as in Example 1 except that the nanofiber sheet was not used, and used as a measurement sample.
Using the obtained measurement sample, the amount of change in skin temperature was determined in the same manner as in Example 1. The results are shown in FIG.

  From the results of Table 1 and FIG. 2, the sheet of Example 1 using PVA nanofibers compared to Comparative Example 1 without a sheet of Comparative Examples 1 and 2 using a rayon nonwoven fabric or a polyolefin nonwoven fabric or a nanofiber sheet layer, It was revealed that the cooling effect was extremely high and the effect was sustained well.

[Example 2]
The same as in Example 1 except that the nanofiber sheet B obtained in Production Example 2 (polyurethane (ASPU-116 manufactured by DIC Corporation) was used instead of polyvinyl alcohol as the polymer constituting the nanofiber) was used. Thus, a laminated sheet having the structure shown in Table 2 was obtained, and the amount of change in skin temperature when applied to the skin was determined. These results are shown in FIG.

[Example 3]
Except for changing the amount of water contained in the gel, a laminated sheet having the structure shown in Table 2 was obtained in the same manner as in Example 1, and the amount of change in skin temperature when applied to the skin was determined. These results are shown in FIG.

  From the results of Table 2 and FIG. 3, it can be seen that the laminated sheets of Examples 1 to 3 exhibit a high cooling effect due to the gradual decrease in skin temperature over time after application. In particular, when Example 1 and Example 2 of the same water-containing polymer gel layer are compared, Example 1 in which nanofiber sheets formed from hydrophilic polymer compounds are laminated is formed from a hydrophobic polymer compound. It can also be seen that a higher cooling effect can be maintained as compared to Example 2 in which the nanofiber sheets were laminated. Furthermore, the laminated sheet of Example 1 had a pleasant cooling sensation with no irritation sensation, with the cooling sensation at the time of skin application being sustained. It can also be seen that the laminated sheet of Example 1 has a higher cooling effect than the laminated sheet of Example 3 having a low water content.

[Example 4]
The structure shown in Table 3 is the same as in Example 1 except that the thickness of the hydrous polymer gel layer is adjusted to 1.5 mm and the nanofiber sheet C (average fiber diameter 394 nm) obtained in Production Example 3 is used. The amount of change in skin temperature when the laminated sheet was obtained and applied to the skin was determined. The results are shown in FIG.

[Example 5]
A laminated sheet having the structure shown in Table 3 was obtained in the same manner as in Example 1 except that the thickness of the hydrous polymer gel layer was adjusted to 1.5 mm, and the amount of change in skin temperature when applied to the skin was determined. The results are shown in FIG.

[Comparative Example 4]
When the thickness of the hydrous polymer gel layer was adjusted to 1.5 mm and a single layer sheet having the structure shown in Table 3 was obtained and applied to the skin in the same manner as in Example 1 except that the nanofiber sheet was not used. The amount of change in skin temperature was determined. The results are shown in FIG.

[Comparative Example 5]
Skin when affixed to the skin in the same manner as in Example 1 using a commercially available cooling sheet formed by forming a hydrous polymer gel layer having a layer thickness of about 2 to 3 mm on a nonwoven fabric having an average fiber diameter of about 5 to 20 μm The amount of temperature change was determined. The results are shown in FIG.

When Example 4 and Example 5 are compared, the cooling effect immediately after the sheet is the same, but the skin temperature change after about 5 minutes after application is an example in which nanofiber sheets with smaller fiber diameters are laminated. It can be seen that 4 is larger and a higher cooling effect can be obtained. On the other hand, in Comparative Example 4, although the skin temperature change immediately after application was large, the skin temperature change was not observed with the passage of time, and the continuous cooling effect was insufficient. Moreover, although the skin temperature change immediately after sticking is large also in the comparative example 5, it turns out that a skin temperature begins to raise rapidly after 1 minute and a cooling effect is impaired rapidly.
From these results, if the laminated sheet of the present invention that combines the water-containing polymer gel layer and the nanofiber layer is pasted, not only is it excellent in the cooling effect immediately after the pasting, but also the cooling effect is continued continuously after that, for a long time. It was revealed that an excellent cooling feeling can be obtained over a long period of time.

[Example 6]
A laminated sheet having the structure shown in Table 4 was prepared in the same manner as in Example 1 except that menthyl lactate was heated and dissolved in PEG400 (Sanyo Kasei Kogyo Co., Ltd.) and blended into the hydrogel layer. A sensory evaluation was performed. The results are shown in FIG.

《Sense evaluation method》
The sheets of Example 1 and Example 6 were affixed to the forehead of three professional panelists in a 28 ° C., 60% RH environment, and the cooling sensation was evaluated. The sensory evaluation after sticking the sheet was scored as follows and decided by consultation.
Sensory score 4: Very cold 3: Cold 2: Slightly cold 1: Slightly cold 0: No feeling -1: Lubricant

  The cooling effect of the sticking site was almost the same between Example 1 and Example 6, but the cooling sensation was stronger in the sheet of Example 6 than in the sheet of Example 1 as shown in FIG. Furthermore, the cold feeling lasted for more than 30 minutes.

Claims (7)

A sheet for skin application in which a nanofiber layer having a network structure formed by nanofibers having an average fiber diameter of 50 nm or more and less than 2000 nm is laminated on a hydrous polymer gel layer.   The sheet for skin application according to claim 1, wherein the nanofiber is formed from a hydrophilic polymer. The sheet for skin application according to claim 1 or 2 , wherein the hydrous polymer gel layer has a thickness of 0.01 to 2 mm. The sheet for skin application according to any one of claims 1 to 3 , wherein the hydrous polymer gel layer contains 40 to 99% by mass of water. The sheet for skin application according to any one of claims 1 to 4 , wherein the water-containing polymer gel layer and / or the nanofiber layer contains a cooling agent. The cooling sensation agent is one or more selected from 1-menthol, menthyl lactate and camphor, and the content of the cooling sensation agent in the water-containing polymer gel layer or nanofiber layer is 0.0001 to 10% by mass. The skin patch sheet according to any one of claims 1 to 5 . The sheet for skin application according to any one of claims 1 to 6 , which is used for cooling human skin.